A new method for isolating physiologically active Mg-protoporphyrin

Research output: Contribution to journalArticle


Mg-protoporphyrin monomethyl ester (MPE) is a biosynthetic intermediate of chlorophyll and converted by MPE cyclase to protochlorophyllide.
Limited availability of MPE has so far hampered cyclase research. In a new, simplified, method MPE was prepared from freeze dried bchE
mutant Rhodobacter capsulatus DB575 cells by extraction with acetone/H2O/25% NH3. Isolated MPE was identified by absorption and fluorescence
spectroscopy, and its purity was analyzed by HPLC. The extracted MPE was dried and redissolved in buffered DMSO and its substrate
activity is shown by enzymatic cyclase assays. A linear time course was observed for MPE conversion to protochlorophyllide by enzymes from
barley etioplasts. Our innovation of freeze drying the R. capsulatus cells before extraction provides a high yield method for MPE, which is significantly
faster and more reproducible than previous extraction methods.


  • Simon Gough
  • Kamila Rzeznicka
  • Ragna Peterson Wulff
  • José da Cruz Francisco
  • Andreas Hansson
  • Poul Erik Jensen
  • Mats Hansson
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biochemistry and Molecular Biology
  • Biological Sciences


  • Mg-protoporphyrin monomethyl ester, MPE, Hordeum vulgare, Cyclase, Rhodobacter capsulatus, Chlorophyll biosynthesis
Original languageEnglish
Pages (from-to)932-936
JournalPlant Physiology and Biochemistry
Issue number12
Publication statusPublished - 2007
Publication categoryResearch